--- /dev/null
+/*
+ * TI EDMA DMA engine driver
+ *
+ * Copyright 2012 Texas Instruments
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <mach/edma.h>
+
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+/*
+ * This will go away when the private EDMA API is folded
+ * into this driver and the platform device(s) are
+ * instantiated in the arch code. We can only get away
+ * with this simplification because DA8XX may not be built
+ * in the same kernel image with other DaVinci parts. This
+ * avoids having to sprinkle dmaengine driver platform devices
+ * and data throughout all the existing board files.
+ */
+#ifdef CONFIG_ARCH_DAVINCI_DA8XX
+#define EDMA_CTLRS 2
+#define EDMA_CHANS 32
+#else
+#define EDMA_CTLRS 1
+#define EDMA_CHANS 64
+#endif /* CONFIG_ARCH_DAVINCI_DA8XX */
+
+/* Max of 16 segments per channel to conserve PaRAM slots */
+#define MAX_NR_SG 16
+#define EDMA_MAX_SLOTS MAX_NR_SG
+#define EDMA_DESCRIPTORS 16
+
+struct edma_desc {
+ struct virt_dma_desc vdesc;
+ struct list_head node;
+ int absync;
+ int pset_nr;
+ struct edmacc_param pset[0];
+};
+
+struct edma_cc;
+
+struct edma_chan {
+ struct virt_dma_chan vchan;
+ struct list_head node;
+ struct edma_desc *edesc;
+ struct edma_cc *ecc;
+ int ch_num;
+ bool alloced;
+ int slot[EDMA_MAX_SLOTS];
+ dma_addr_t addr;
+ int addr_width;
+ int maxburst;
+};
+
+struct edma_cc {
+ int ctlr;
+ struct dma_device dma_slave;
+ struct edma_chan slave_chans[EDMA_CHANS];
+ int num_slave_chans;
+ int dummy_slot;
+};
+
+static inline struct edma_cc *to_edma_cc(struct dma_device *d)
+{
+ return container_of(d, struct edma_cc, dma_slave);
+}
+
+static inline struct edma_chan *to_edma_chan(struct dma_chan *c)
+{
+ return container_of(c, struct edma_chan, vchan.chan);
+}
+
+static inline struct edma_desc
+*to_edma_desc(struct dma_async_tx_descriptor *tx)
+{
+ return container_of(tx, struct edma_desc, vdesc.tx);
+}
+
+static void edma_desc_free(struct virt_dma_desc *vdesc)
+{
+ kfree(container_of(vdesc, struct edma_desc, vdesc));
+}
+
+/* Dispatch a queued descriptor to the controller (caller holds lock) */
+static void edma_execute(struct edma_chan *echan)
+{
+ struct virt_dma_desc *vdesc = vchan_next_desc(&echan->vchan);
+ struct edma_desc *edesc;
+ int i;
+
+ if (!vdesc) {
+ echan->edesc = NULL;
+ return;
+ }
+
+ list_del(&vdesc->node);
+
+ echan->edesc = edesc = to_edma_desc(&vdesc->tx);
+
+ /* Write descriptor PaRAM set(s) */
+ for (i = 0; i < edesc->pset_nr; i++) {
+ edma_write_slot(echan->slot[i], &edesc->pset[i]);
+ dev_dbg(echan->vchan.chan.device->dev,
+ "\n pset[%d]:\n"
+ " chnum\t%d\n"
+ " slot\t%d\n"
+ " opt\t%08x\n"
+ " src\t%08x\n"
+ " dst\t%08x\n"
+ " abcnt\t%08x\n"
+ " ccnt\t%08x\n"
+ " bidx\t%08x\n"
+ " cidx\t%08x\n"
+ " lkrld\t%08x\n",
+ i, echan->ch_num, echan->slot[i],
+ edesc->pset[i].opt,
+ edesc->pset[i].src,
+ edesc->pset[i].dst,
+ edesc->pset[i].a_b_cnt,
+ edesc->pset[i].ccnt,
+ edesc->pset[i].src_dst_bidx,
+ edesc->pset[i].src_dst_cidx,
+ edesc->pset[i].link_bcntrld);
+ /* Link to the previous slot if not the last set */
+ if (i != (edesc->pset_nr - 1))
+ edma_link(echan->slot[i], echan->slot[i+1]);
+ /* Final pset links to the dummy pset */
+ else
+ edma_link(echan->slot[i], echan->ecc->dummy_slot);
+ }
+
+ edma_start(echan->ch_num);
+}
+
+static int edma_terminate_all(struct edma_chan *echan)
+{
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&echan->vchan.lock, flags);
+
+ /*
+ * Stop DMA activity: we assume the callback will not be called
+ * after edma_dma() returns (even if it does, it will see
+ * echan->edesc is NULL and exit.)
+ */
+ if (echan->edesc) {
+ echan->edesc = NULL;
+ edma_stop(echan->ch_num);
+ }
+
+ vchan_get_all_descriptors(&echan->vchan, &head);
+ spin_unlock_irqrestore(&echan->vchan.lock, flags);
+ vchan_dma_desc_free_list(&echan->vchan, &head);
+
+ return 0;
+}
+
+
+static int edma_slave_config(struct edma_chan *echan,
+ struct dma_slave_config *config)
+{
+ if ((config->src_addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES) ||
+ (config->dst_addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES))
+ return -EINVAL;
+
+ if (config->direction == DMA_MEM_TO_DEV) {
+ if (config->dst_addr)
+ echan->addr = config->dst_addr;
+ if (config->dst_addr_width)
+ echan->addr_width = config->dst_addr_width;
+ if (config->dst_maxburst)
+ echan->maxburst = config->dst_maxburst;
+ } else if (config->direction == DMA_DEV_TO_MEM) {
+ if (config->src_addr)
+ echan->addr = config->src_addr;
+ if (config->src_addr_width)
+ echan->addr_width = config->src_addr_width;
+ if (config->src_maxburst)
+ echan->maxburst = config->src_maxburst;
+ }
+
+ return 0;
+}
+
+static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ int ret = 0;
+ struct dma_slave_config *config;
+ struct edma_chan *echan = to_edma_chan(chan);
+
+ switch (cmd) {
+ case DMA_TERMINATE_ALL:
+ edma_terminate_all(echan);
+ break;
+ case DMA_SLAVE_CONFIG:
+ config = (struct dma_slave_config *)arg;
+ ret = edma_slave_config(echan, config);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ return ret;
+}
+
+static struct dma_async_tx_descriptor *edma_prep_slave_sg(
+ struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_transfer_direction direction,
+ unsigned long tx_flags, void *context)
+{
+ struct edma_chan *echan = to_edma_chan(chan);
+ struct device *dev = chan->device->dev;
+ struct edma_desc *edesc;
+ struct scatterlist *sg;
+ int i;
+ int acnt, bcnt, ccnt, src, dst, cidx;
+ int src_bidx, dst_bidx, src_cidx, dst_cidx;
+
+ if (unlikely(!echan || !sgl || !sg_len))
+ return NULL;
+
+ if (echan->addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) {
+ dev_err(dev, "Undefined slave buswidth\n");
+ return NULL;
+ }
+
+ if (sg_len > MAX_NR_SG) {
+ dev_err(dev, "Exceeded max SG segments %d > %d\n",
+ sg_len, MAX_NR_SG);
+ return NULL;
+ }
+
+ edesc = kzalloc(sizeof(*edesc) + sg_len *
+ sizeof(edesc->pset[0]), GFP_ATOMIC);
+ if (!edesc) {
+ dev_dbg(dev, "Failed to allocate a descriptor\n");
+ return NULL;
+ }
+
+ edesc->pset_nr = sg_len;
+
+ for_each_sg(sgl, sg, sg_len, i) {
+ /* Allocate a PaRAM slot, if needed */
+ if (echan->slot[i] < 0) {
+ echan->slot[i] =
+ edma_alloc_slot(EDMA_CTLR(echan->ch_num),
+ EDMA_SLOT_ANY);
+ if (echan->slot[i] < 0) {
+ dev_err(dev, "Failed to allocate slot\n");
+ return NULL;
+ }
+ }
+
+ acnt = echan->addr_width;
+
+ /*
+ * If the maxburst is equal to the fifo width, use
+ * A-synced transfers. This allows for large contiguous
+ * buffer transfers using only one PaRAM set.
+ */
+ if (echan->maxburst == 1) {
+ edesc->absync = false;
+ ccnt = sg_dma_len(sg) / acnt / (SZ_64K - 1);
+ bcnt = sg_dma_len(sg) / acnt - ccnt * (SZ_64K - 1);
+ if (bcnt)
+ ccnt++;
+ else
+ bcnt = SZ_64K - 1;
+ cidx = acnt;
+ /*
+ * If maxburst is greater than the fifo address_width,
+ * use AB-synced transfers where A count is the fifo
+ * address_width and B count is the maxburst. In this
+ * case, we are limited to transfers of C count frames
+ * of (address_width * maxburst) where C count is limited
+ * to SZ_64K-1. This places an upper bound on the length
+ * of an SG segment that can be handled.
+ */
+ } else {
+ edesc->absync = true;
+ bcnt = echan->maxburst;
+ ccnt = sg_dma_len(sg) / (acnt * bcnt);
+ if (ccnt > (SZ_64K - 1)) {
+ dev_err(dev, "Exceeded max SG segment size\n");
+ return NULL;
+ }
+ cidx = acnt * bcnt;
+ }
+
+ if (direction == DMA_MEM_TO_DEV) {
+ src = sg_dma_address(sg);
+ dst = echan->addr;
+ src_bidx = acnt;
+ src_cidx = cidx;
+ dst_bidx = 0;
+ dst_cidx = 0;
+ } else {
+ src = echan->addr;
+ dst = sg_dma_address(sg);
+ src_bidx = 0;
+ src_cidx = 0;
+ dst_bidx = acnt;
+ dst_cidx = cidx;
+ }
+
+ edesc->pset[i].opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num));
+ /* Configure A or AB synchronized transfers */
+ if (edesc->absync)
+ edesc->pset[i].opt |= SYNCDIM;
+ /* If this is the last set, enable completion interrupt flag */
+ if (i == sg_len - 1)
+ edesc->pset[i].opt |= TCINTEN;
+
+ edesc->pset[i].src = src;
+ edesc->pset[i].dst = dst;
+
+ edesc->pset[i].src_dst_bidx = (dst_bidx << 16) | src_bidx;
+ edesc->pset[i].src_dst_cidx = (dst_cidx << 16) | src_cidx;
+
+ edesc->pset[i].a_b_cnt = bcnt << 16 | acnt;
+ edesc->pset[i].ccnt = ccnt;
+ edesc->pset[i].link_bcntrld = 0xffffffff;
+
+ }
+
+ return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
+}
+
+static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
+{
+ struct edma_chan *echan = data;
+ struct device *dev = echan->vchan.chan.device->dev;
+ struct edma_desc *edesc;
+ unsigned long flags;
+
+ /* Stop the channel */
+ edma_stop(echan->ch_num);
+
+ switch (ch_status) {
+ case DMA_COMPLETE:
+ dev_dbg(dev, "transfer complete on channel %d\n", ch_num);
+
+ spin_lock_irqsave(&echan->vchan.lock, flags);
+
+ edesc = echan->edesc;
+ if (edesc) {
+ edma_execute(echan);
+ vchan_cookie_complete(&edesc->vdesc);
+ }
+
+ spin_unlock_irqrestore(&echan->vchan.lock, flags);
+
+ break;
+ case DMA_CC_ERROR:
+ dev_dbg(dev, "transfer error on channel %d\n", ch_num);
+ break;
+ default:
+ break;
+ }
+}
+
+/* Alloc channel resources */
+static int edma_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct edma_chan *echan = to_edma_chan(chan);
+ struct device *dev = chan->device->dev;
+ int ret;
+ int a_ch_num;
+ LIST_HEAD(descs);
+
+ a_ch_num = edma_alloc_channel(echan->ch_num, edma_callback,
+ chan, EVENTQ_DEFAULT);
+
+ if (a_ch_num < 0) {
+ ret = -ENODEV;
+ goto err_no_chan;
+ }
+
+ if (a_ch_num != echan->ch_num) {
+ dev_err(dev, "failed to allocate requested channel %u:%u\n",
+ EDMA_CTLR(echan->ch_num),
+ EDMA_CHAN_SLOT(echan->ch_num));
+ ret = -ENODEV;
+ goto err_wrong_chan;
+ }
+
+ echan->alloced = true;
+ echan->slot[0] = echan->ch_num;
+
+ dev_info(dev, "allocated channel for %u:%u\n",
+ EDMA_CTLR(echan->ch_num), EDMA_CHAN_SLOT(echan->ch_num));
+
+ return 0;
+
+err_wrong_chan:
+ edma_free_channel(a_ch_num);
+err_no_chan:
+ return ret;
+}
+
+/* Free channel resources */
+static void edma_free_chan_resources(struct dma_chan *chan)
+{
+ struct edma_chan *echan = to_edma_chan(chan);
+ struct device *dev = chan->device->dev;
+ int i;
+
+ /* Terminate transfers */
+ edma_stop(echan->ch_num);
+
+ vchan_free_chan_resources(&echan->vchan);
+
+ /* Free EDMA PaRAM slots */
+ for (i = 1; i < EDMA_MAX_SLOTS; i++) {
+ if (echan->slot[i] >= 0) {
+ edma_free_slot(echan->slot[i]);
+ echan->slot[i] = -1;
+ }
+ }
+
+ /* Free EDMA channel */
+ if (echan->alloced) {
+ edma_free_channel(echan->ch_num);
+ echan->alloced = false;
+ }
+
+ dev_info(dev, "freeing channel for %u\n", echan->ch_num);
+}
+
+/* Send pending descriptor to hardware */
+static void edma_issue_pending(struct dma_chan *chan)
+{
+ struct edma_chan *echan = to_edma_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&echan->vchan.lock, flags);
+ if (vchan_issue_pending(&echan->vchan) && !echan->edesc)
+ edma_execute(echan);
+ spin_unlock_irqrestore(&echan->vchan.lock, flags);
+}
+
+static size_t edma_desc_size(struct edma_desc *edesc)
+{
+ int i;
+ size_t size;
+
+ if (edesc->absync)
+ for (size = i = 0; i < edesc->pset_nr; i++)
+ size += (edesc->pset[i].a_b_cnt & 0xffff) *
+ (edesc->pset[i].a_b_cnt >> 16) *
+ edesc->pset[i].ccnt;
+ else
+ size = (edesc->pset[0].a_b_cnt & 0xffff) *
+ (edesc->pset[0].a_b_cnt >> 16) +
+ (edesc->pset[0].a_b_cnt & 0xffff) *
+ (SZ_64K - 1) * edesc->pset[0].ccnt;
+
+ return size;
+}
+
+/* Check request completion status */
+static enum dma_status edma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct edma_chan *echan = to_edma_chan(chan);
+ struct virt_dma_desc *vdesc;
+ enum dma_status ret;
+ unsigned long flags;
+
+ ret = dma_cookie_status(chan, cookie, txstate);
+ if (ret == DMA_SUCCESS || !txstate)
+ return ret;
+
+ spin_lock_irqsave(&echan->vchan.lock, flags);
+ vdesc = vchan_find_desc(&echan->vchan, cookie);
+ if (vdesc) {
+ txstate->residue = edma_desc_size(to_edma_desc(&vdesc->tx));
+ } else if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie) {
+ struct edma_desc *edesc = echan->edesc;
+ txstate->residue = edma_desc_size(edesc);
+ } else {
+ txstate->residue = 0;
+ }
+ spin_unlock_irqrestore(&echan->vchan.lock, flags);
+
+ return ret;
+}
+
+static void __init edma_chan_init(struct edma_cc *ecc,
+ struct dma_device *dma,
+ struct edma_chan *echans)
+{
+ int i, j;
+
+ for (i = 0; i < EDMA_CHANS; i++) {
+ struct edma_chan *echan = &echans[i];
+ echan->ch_num = EDMA_CTLR_CHAN(ecc->ctlr, i);
+ echan->ecc = ecc;
+ echan->vchan.desc_free = edma_desc_free;
+
+ vchan_init(&echan->vchan, dma);
+
+ INIT_LIST_HEAD(&echan->node);
+ for (j = 0; j < EDMA_MAX_SLOTS; j++)
+ echan->slot[j] = -1;
+ }
+}
+
+static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma,
+ struct device *dev)
+{
+ dma->device_prep_slave_sg = edma_prep_slave_sg;
+ dma->device_alloc_chan_resources = edma_alloc_chan_resources;
+ dma->device_free_chan_resources = edma_free_chan_resources;
+ dma->device_issue_pending = edma_issue_pending;
+ dma->device_tx_status = edma_tx_status;
+ dma->device_control = edma_control;
+ dma->dev = dev;
+
+ INIT_LIST_HEAD(&dma->channels);
+}
+
+static int __devinit edma_probe(struct platform_device *pdev)
+{
+ struct edma_cc *ecc;
+ int ret;
+
+ ecc = devm_kzalloc(&pdev->dev, sizeof(*ecc), GFP_KERNEL);
+ if (!ecc) {
+ dev_err(&pdev->dev, "Can't allocate controller\n");
+ return -ENOMEM;
+ }
+
+ ecc->ctlr = pdev->id;
+ ecc->dummy_slot = edma_alloc_slot(ecc->ctlr, EDMA_SLOT_ANY);
+ if (ecc->dummy_slot < 0) {
+ dev_err(&pdev->dev, "Can't allocate PaRAM dummy slot\n");
+ return -EIO;
+ }
+
+ dma_cap_zero(ecc->dma_slave.cap_mask);
+ dma_cap_set(DMA_SLAVE, ecc->dma_slave.cap_mask);
+
+ edma_dma_init(ecc, &ecc->dma_slave, &pdev->dev);
+
+ edma_chan_init(ecc, &ecc->dma_slave, ecc->slave_chans);
+
+ ret = dma_async_device_register(&ecc->dma_slave);
+ if (ret)
+ goto err_reg1;
+
+ platform_set_drvdata(pdev, ecc);
+
+ dev_info(&pdev->dev, "TI EDMA DMA engine driver\n");
+
+ return 0;
+
+err_reg1:
+ edma_free_slot(ecc->dummy_slot);
+ return ret;
+}
+
+static int __devexit edma_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct edma_cc *ecc = dev_get_drvdata(dev);
+
+ dma_async_device_unregister(&ecc->dma_slave);
+ edma_free_slot(ecc->dummy_slot);
+
+ return 0;
+}
+
+static struct platform_driver edma_driver = {
+ .probe = edma_probe,
+ .remove = __devexit_p(edma_remove),
+ .driver = {
+ .name = "edma-dma-engine",
+ .owner = THIS_MODULE,
+ },
+};
+
+bool edma_filter_fn(struct dma_chan *chan, void *param)
+{
+ if (chan->device->dev->driver == &edma_driver.driver) {
+ struct edma_chan *echan = to_edma_chan(chan);
+ unsigned ch_req = *(unsigned *)param;
+ return ch_req == echan->ch_num;
+ }
+ return false;
+}
+EXPORT_SYMBOL(edma_filter_fn);
+
+static struct platform_device *pdev0, *pdev1;
+
+static const struct platform_device_info edma_dev_info0 = {
+ .name = "edma-dma-engine",
+ .id = 0,
+ .dma_mask = DMA_BIT_MASK(32),
+};
+
+static const struct platform_device_info edma_dev_info1 = {
+ .name = "edma-dma-engine",
+ .id = 1,
+ .dma_mask = DMA_BIT_MASK(32),
+};
+
+static int edma_init(void)
+{
+ int ret = platform_driver_register(&edma_driver);
+
+ if (ret == 0) {
+ pdev0 = platform_device_register_full(&edma_dev_info0);
+ if (IS_ERR(pdev0)) {
+ platform_driver_unregister(&edma_driver);
+ ret = PTR_ERR(pdev0);
+ goto out;
+ }
+ }
+
+ if (EDMA_CTLRS == 2) {
+ pdev1 = platform_device_register_full(&edma_dev_info1);
+ if (IS_ERR(pdev1)) {
+ platform_driver_unregister(&edma_driver);
+ platform_device_unregister(pdev0);
+ ret = PTR_ERR(pdev1);
+ }
+ }
+
+out:
+ return ret;
+}
+subsys_initcall(edma_init);
+
+static void __exit edma_exit(void)
+{
+ platform_device_unregister(pdev0);
+ if (pdev1)
+ platform_device_unregister(pdev1);
+ platform_driver_unregister(&edma_driver);
+}
+module_exit(edma_exit);
+
+MODULE_AUTHOR("Matt Porter <mporter@ti.com>");
+MODULE_DESCRIPTION("TI EDMA DMA engine driver");
+MODULE_LICENSE("GPL v2");
projects / ~andy / linux / commitdiff